The present invention relates to assemblies and methods for online partial discharge testing, and more particularly to assemblies and methods of installing such assemblies for conducting online partial discharge testing.
Partial discharge sensing can be used to assess the condition of power cables. More particularly, partial discharge sensing can be used to detect deterioration of insulation of power cables by detecting high frequency currents that are created by small gaps, voids, cracks or other degradation in power cable insulation. Online partial discharge sensing refers to time domain and frequency domain testing conducted on objects that remain electrically energized during testing.
Typically, a partial discharge sensing system includes a partial discharge sensor, a signal analyzer, and a signal cable for carrying electrical signals between the sensor and the signal analyzer. In order to conduct a partial discharge test, an operator positions the sensor at a test location on a power cable. Known online partial discharge testing systems utilize split-core sensors, which require the operator to clamp the split core sensor around the energized power cable. Next, the operator manually conducts a partial discharge test using the signal analyzer.
In order to conduct testing on power cables using a known split-core sensor, the operator must be in close proximity to the energized power cables and other charge-carrying components, which may be located within an enclosure that limits operator access and maneuverability. This presents a safety hazard to operators, who risk electrical shock, electrocution, arc blast, and other serious injury from such electrically energized equipment. Operators typically wear protective coverings, such as protective gloves, etc. However, even with protective coverings, it is desired to keep operators as far away from energized equipment as possible to promote operator safety. Yet connecting online partial discharge testing equipment for a distance presents numerous difficulties, including ease of use for operators wearing protective coverings (e.g., thick protective gloves that restrict manual dexterity).
Thus, an alternative online partial discharge testing assembly is desired.